We have developed a variety of tasks to activate regions of interest in functional neuroimaging studies. 1. We are developing a Continuous Performance Test of attention and encoding to be used in event related fMRI. While behavioral deficits have been widely reported in schizophrenic patients, the neural substrate of this task has yet to be elucidated. 2. We developed a carefully matched set of verbal fluency tasks to examine the relation between semantic processing, thought disorder, and neurophysiology in schizophrenia using PET CBF methods. We arel also using a semantic processing task in fMRI to determine the physiologic concomitants of aberrations in semantic space. 3. To examine the levels of processing account of episodic memory we devised a series or recognition memory tasks. We also paid special attention to the development of a control task that would not involve active processing so as to better observe hippocampal activation. - cognition schizophrenia neuroimaging - Human Subjects: Interview, Questionaires, or Surveys Only